1. Field of the Invention
The invention relates to a traffic control system, traffic control method, communication device, and computer program for controlling communication traffic (called just “traffic” hereinbelow).
2. Description of the Related Art
Recently, many kinds of applications have been used that perform communication because of the spread of the Internet. A plurality of applications such as one for sending and receiving e-mail, gaining access to a Website, exchanging files, and playing a computer game using a communication channel is installed in, for example, one personal computer for operation. Traffic is generated for each application when those applications operate simultaneously. One communication circuit is generally shared as an output circuit for the traffic. Under such circumstances, software is known that is exclusively used for controlling the traffic produced at a communication terminal (for example, a personal computer). See, for example, “Netnice,” Retrieved on Aug. 11, 2005 from the World Wide Web: http://www.netnice.org/index-ja.html. The conventional traffic control software is a tool for controlling traffic based on the intention of a user himself at a communication terminal.
The prior art described above can control traffic on the side of the communication terminal, but cannot control traffic generated at the communication terminal, on the side of a communication network. Because of this, for example, communication service, which uses a UDP (User Datagram Protocol) as a protocol, can generate traffic from each communication terminal without being limited to the use rate of a communication network. It is expected that communication capacity of the communication network will be low. Since it is difficult to predict an amount of traffic processed in a communication network, proper facilities and design of communication networks is difficult. Moreover, when a plurality of users shares one communication circuit, occupation of the circuit by a specific application of a specific user cannot be prevented.
For these reasons, it is desirable to control the traffic generated by the specific application of the specific user, on the side of the communication network.
It is considered that traffic produced at a communication terminal can be equally limited. However, when the traffic at a communication terminal is equally limited, QoS (Quality of Service) guarantee demanded by each application cannot be controlled, and sufficient quality of communication service cannot be maintained. There is a need to solve such inconveniences.